Conformational effects on high-spin organic molecules

Scott K Silverman, Dennis A. Dougherty

Research output: Contribution to journalArticle

Abstract

The ability of m-phenylene to ferromagnetically couple spin-containing substituents that are substantially twisted out of conjugation is investigated. The "bis(TMM)" strategy is employed, in which two triplet TMM biradicals are linked through m-phenylene to produce relatively stable, organic tetraradicals that are characterized by EPR spectroscopy. Under conditions of moderate twisting (4), ferromagnetic coupling is seen, and the tetraradical has a quintet ground state. Severely twisting both TMMs as in 13 disrupts spin communication, and two noninteracting triplets are produced. This is in contrast to other highly twisted m-phenylene derivatives, in which antiferromagnetic coupling has been observed. Surprisingly, severely twisting only one TMM (14) still produces ferromagnetic coupling and a quintet ground state through a spin polarization mechanism analogous to that proposed for 90° twisted ethylene. Several ring-constrained TMMs (17-19) are investigated as models for more nearly planar systems.

Original languageEnglish (US)
Pages (from-to)13273-13283
Number of pages11
JournalJournal of physical chemistry
Volume97
Issue number50
DOIs
StatePublished - Jan 1 1993

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twisting
Ground state
Spin polarization
Molecules
Paramagnetic resonance
molecules
Ethylene
ground state
Spectroscopy
Derivatives
conjugation
Communication
ethylene
communication
rings
polarization
spectroscopy

ASJC Scopus subject areas

  • Engineering(all)
  • Physical and Theoretical Chemistry

Cite this

Conformational effects on high-spin organic molecules. / Silverman, Scott K; Dougherty, Dennis A.

In: Journal of physical chemistry, Vol. 97, No. 50, 01.01.1993, p. 13273-13283.

Research output: Contribution to journalArticle

Silverman, Scott K ; Dougherty, Dennis A. / Conformational effects on high-spin organic molecules. In: Journal of physical chemistry. 1993 ; Vol. 97, No. 50. pp. 13273-13283.
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